The present invention relates to an automatic identification system for objects or persons by remote interrogation. It has numerous applications, particularly in the field of detecting persons carrying badges or in the accounting and/or checking of stocked goods or goods sold in stores.
In known automatic identification systems, it is possible to recognize an object or a person carrying respectively a tag or a badge provided with a code circuit and passing under or in the vicinity of a monitoring gate. This gate then emits RF (radio frequency) pulses towards the tag or badge. These pulses are used for energizing the tag and interrogating the code stored therein. The code of the tag or badge carried by the object or person is in this way recognized. Such a device is described in EP-A-241 148.
Such systems do not make it possible to recognize in a quasi-simultaneous manner a plurality of objects or persons by the successive determination of each bit constituting the code contained in the tag or badge of said objects or persons and therefore do not make it possible to process a large number of objects.